KVM: arm/arm64: vgic: Check return value for kvm_register_vgic_device

kvm_register_device_ops() can return an error, so lets check its return
value and propagate this up the call chain.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

4 files changed, 31 insertions, 12 deletions

diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 0130c4b147b7..2f24f13c6c90 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -210,20 +210,24 @@ static void vgic_destroy(struct kvm_device *dev)
         kfree(dev);
 }
 
-void kvm_register_vgic_device(unsigned long type)
+int kvm_register_vgic_device(unsigned long type)
 {
+        int ret = -ENODEV;
+
         switch (type) {
         case KVM_DEV_TYPE_ARM_VGIC_V2:
-                kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
-                                        KVM_DEV_TYPE_ARM_VGIC_V2);
+                ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
+                                              KVM_DEV_TYPE_ARM_VGIC_V2);
                 break;
 #ifdef CONFIG_KVM_ARM_VGIC_V3
         case KVM_DEV_TYPE_ARM_VGIC_V3:
-                kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
-                                        KVM_DEV_TYPE_ARM_VGIC_V3);
+                ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
+                                              KVM_DEV_TYPE_ARM_VGIC_V3);
                 break;
 #endif
         }
+
+        return ret;
 }
 
 /** vgic_attr_regs_access: allows user space to read/write VGIC registers
@@ -428,4 +432,3 @@ struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 };
 
 #endif /* CONFIG_KVM_ARM_VGIC_V3 */
-
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
index e31405ee5515..079bf670c451 100644
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -332,20 +332,25 @@ int vgic_v2_probe(const struct gic_kvm_info *info)
         vtr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VTR);
         kvm_vgic_global_state.nr_lr = (vtr & 0x3f) + 1;
 
+        ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
+        if (ret) {
+                kvm_err("Cannot register GICv2 KVM device\n");
+                iounmap(kvm_vgic_global_state.vctrl_base);
+                return ret;
+        }
+
         ret = create_hyp_io_mappings(kvm_vgic_global_state.vctrl_base,
                                      kvm_vgic_global_state.vctrl_base +
                                          resource_size(&info->vctrl),
                                      info->vctrl.start);
-
         if (ret) {
                 kvm_err("Cannot map VCTRL into hyp\n");
+                kvm_unregister_device_ops(KVM_DEV_TYPE_ARM_VGIC_V2);
                 iounmap(kvm_vgic_global_state.vctrl_base);
                 return ret;
         }
 
         kvm_vgic_global_state.can_emulate_gicv2 = true;
-        kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
-
         kvm_vgic_global_state.vcpu_base = info->vcpu.start;
         kvm_vgic_global_state.type = VGIC_V2;
         kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 346b4ad12b49..e48a22e9ee40 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -296,6 +296,7 @@ out:
 int vgic_v3_probe(const struct gic_kvm_info *info)
 {
         u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
+        int ret;
 
         /*
          * The ListRegs field is 5 bits, but there is a architectural
@@ -319,12 +320,22 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
         } else {
                 kvm_vgic_global_state.vcpu_base = info->vcpu.start;
                 kvm_vgic_global_state.can_emulate_gicv2 = true;
-                kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
+                ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
+                if (ret) {
+                        kvm_err("Cannot register GICv2 KVM device.\n");
+                        return ret;
+                }
                 kvm_info("vgic-v2@%llx\n", info->vcpu.start);
         }
+        ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V3);
+        if (ret) {
+                kvm_err("Cannot register GICv3 KVM device.\n");
+                kvm_unregister_device_ops(KVM_DEV_TYPE_ARM_VGIC_V2);
+                return ret;
+        }
+
         if (kvm_vgic_global_state.vcpu_base == 0)
                 kvm_info("disabling GICv2 emulation\n");
-        kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V3);
 
         kvm_vgic_global_state.vctrl_base = NULL;
         kvm_vgic_global_state.type = VGIC_V3;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 7b300ca370b7..c752152e8248 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -124,7 +124,7 @@ static inline int vgic_register_redist_iodevs(struct kvm *kvm,
 }
 #endif
 
-void kvm_register_vgic_device(unsigned long type);
+int kvm_register_vgic_device(unsigned long type);
 int vgic_lazy_init(struct kvm *kvm);
 int vgic_init(struct kvm *kvm);